Improving the shape of US zones

[madsnedergaard]

Description

The current shapes we use for US zones are not ideal and doesn't match the real areas covered by balancing authorities.

As an example, let's use US-CAL-CISO (CAISO):

Our map

CAISO's map

Watttime's map

Our idea of what CAISO covers is obviously pretty different - and the shape of WAPA (the zone that we think takes up the rest) is also really messed up:

Why

The zones were split in #2301 based on this map: https://hifld-geoplatform.opendata.arcgis.com/datasets/control-areas/explore?location=36.714368%2C-115.529758%2C6.94

A contributor also raised this, but maybe it's only for CAISO?

This is also a problem in #3359 where we want to remove some of the retired zones..

Proposed solution

Find better geometries! 😅
And/or: Figure out how to deal with overlaps in the best possible way.

Not saying it's going to be easy, but I think it's worth spending time on!

Also, this one might be useful: https://hifld-geoplatform.opendata.arcgis.com/datasets/9d1099b016e5482c900d657f06f3ac80_0/explore

See also discussions here: #143

Would love comments on this if anyone has an idea on how we can do this better! 🙏